FRANKFURT--The head of Europe's insurance regulator on Wednesday called for stricter oversight of companies that behave more like investment banks, delving deep into activities that pose risks for the entire financial system.

"We need to limit any potential incentive for typical banking risks to be transferred to the insurance sector," Gabriel Bernardino, chairman of the European Insurance and Occupational Pensions Authority, or Eiopa, told a conference.

Regulators are cracking down on the kind of risk-taking activities that led to the 2008 financial crisis, recently drawing up a list of banks deemed big enough to destabilize global markets.

Insurers also have come under increased scrutiny, with the crisis revealing that some of their non-traditional activities can also pose system-wide risk, including credit default swaps, financial guarantees, or leveraging assets to enhance investment returns through securities lending.

Bernardino said such activities "are more vulnerable to financial market developments and more likely to amplify or contribute to systemic risk."

"We should be especially attentive to any kind of maturity transformation and leveraging occurring in the insurance sector," he said.

Write to Ulrike Dauer at ulrike.dauer@wsj.com